6 char externs -- a lint suggestion

[Guy Harris]

> A lint option could be included which would allow one to have it
> check all internal names to be unique up to 'n' significant characters.

Try "lint -p"; on the following program:

	mainxxbar()
	{
	}

	mainxxfoo()
	{
	}

it generates the following diagnostic:

	==============
	name multiply declared
	    mainxx   	futz.c(2) :: futz.c(6)

This also has the effect of checking against a "lint library" for a
portable subset of the standard C library, instead of the full UNIX C
library.

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy